Several hedge funds may have to give back millions of dollars made on their investments with convicted Ponzi schemer Thomas Petters.

Douglas Kelley, the court-appointed receiver for the Minnesota businessman and hedge fund manager’s companies, has sent letters to an unspecified number of hedge funds demanding the return of about $300 million in phony profits paid out by Petters over the years.

Petters was convicted earlier this month of running a $3.65 billion Ponzi scheme. During the trial, it emerged that at least two hedge funds had made about $300 million apiece through his scam. One, a Minnesota hedge fund called Opportunity Finance, allegedly received between $250 million and $300 million in bogus profits, while another, Epsilon Financial Management, got $300 million.

Kelley isn’t targeting just hedge funds: The receiver has also sent letters demanding clawbacks to several nonprofits that received money from Petters, including Petters’ own philanthropic foundation.